Sight for antiaircraft machine guns



June 20, 1933. Y. P. G. L PRIEUR Er AL 1,915,191

vSIGHT FOR ANTIAIRCRAFT MACHINE GUNS Filed oct. 22. 19:50 .ssheets-sheet 1 June 20, 1933. Y. P. G. LE PRIEUR Er AL 1,915,191

SIGHT FOR ANTIAIRCRAFT MACHINE GUNS Filed Oct. 22,1930 6 Sheets-Sheet f2June 20, 1933.

Y. P. G. LE PRIEUR ET AL SIGHT FOR ANTIAIRGRAFT MACHINE GUNS 6Sheets-Sheet 3 Filed 001;. 22, 1930 June-20, 1933- Y. P. G. LE PRIEURx-:T AL 1,915,191 I SIGHT FOR ANTIAVIRCRAFT MACHINE GUNS Filed Oct. 22,1950 6 Sheets-Sheet 4 oo l ,www

June 20, 1933. Y.4 P G. LE PRIEUR Er AL L 1,915,191

I y SIGHT FOR ANTIAIRCRAFT MACHINE' GUNS I -Fi1ed Oct. 22, 193K) 6Shee'ts-Sheet 5 b 1 la 596- be used Patented June zo, 1933 lxz'vnsrAUn'GAsroN'LE Pirnun ANDnUGUsrE LoUIs arconDEL, or raars, 'mancaAssIGNons ro LA rm'zcrsr'orr nonanmv, or

frame, ramon, n conron-arronor smn'r Fon mmmcnm Macallan Guns i l i l iApp'lication led October 22,`1930, Serial No. 490,504, and 'in FranceMarch 13.11930, n

We will first recall the principles according to which are made mostlines of sight-for guns adapted to fire against` aerial movable targets.f

the sight glass or similar instrument is directed towards the target,the gunbarrel v comes automatically into the positlon required forfiring' correctly against this tar et.

To this end thesight glass is set w1th re er- 'ence' to the gun, afterthe two followlng corrections have been taken intoaccount:

(a) The correction due to the varlable d ef- -ormationy of thetrajectory with the varying angles of sight of the target (sight correc--tion' (6)), The correction required bythe displacement of the targetduring the time of A flightV of the projectile (displacement correctionY The sight-correction (Figure l) is based on the well-known rincipleofthe vertical sight. Supposing all) is a gun barrel directed for firingon'a target disposed in its horizontal plane (angle of sight zero), theline of. si ht passes through a foresight b at the end cfg the gun andthrough a point 'c at the end of the vertical back-sight a0. If it isdesired to' flreon a `target at the same distance afs thefirst onebut-the angle of sight of which is s, an easy calculation based. onexperience shows it is suicient to make the gun rotate round a until itsendL is brought to b', the back-sight ac remaining unaltered' providedit continues being vertical.. x v

'As concerns the corrections of displacement', supposing E (Figure 2) isthe actual position of the aircraft, 0 the end of the gun) which is tolire against it, 'the future 'poslition of hev aircraft after a time Tequal to the time of flight of the projectile corresponding to-,a'rangeD equal to OE. If we draw a sinall triangle o ef corresponding to OEF at45 a reduced scale, the following formula may VV0E -oe which means that,if Vis the real speed 'of These lines of sight must besuch that, whenlanarm ef, the arm fo carrying the sight-glass l the gun O such that Oe=1.

being formed. The-said devicehas for its4l the 'aircraft (includingconsequentlythe wind correction) and oe is ygiven a constant value,

say 1, the'following'formula is true;

' irri/l' l ",'TOE'Dn' 1A corrector making useof this formula W1llcomprise'a vertical bacl/Ifsight bie and K belng connected with astationary polnt of Such a corrector has' been described, in the priorpatent to. Yves Le Prieur, No. 1,651,093, of November 29, 1927.

In'this corrector,'the arm parallel to the sight glass is articulated onthe one hand at t la point of the fire-armand on the other hand totheend of a vert-ical rod which is displaced in height so as'to materializethe vecgo tor e f and Whichis displaced laterally to the movable targetfor a length equal to y v5 For this purpose, thevertical rod is mountedin a carriage sliding horizontally in .a

5 cylindrical box with vertical shaft, this box which l,cis adapted tobe raised or lowered in a cylindrical .easing 'with' vertical shaft sois articulated'to the fire-arm andadapted to rotate .in the said casing.rThe elevation is given bya vertical displacement of the box in thecasing; The plane passing through the axis vof the box is directed andalso the vertical rod parallel vto the speed of the aircraft by asuitable rotation of the box Ain the casing, the said rotation beingcontrolled by means of Aan arrow which is directed parallel to theaircraft. An auxiliary device outside the cylindrical casing allows ofthe product i A VT object to displace .a v'suitable rack for the lengthcorresponding to the said product and -r the said racklaterally'displaces the carriage 100 bearing the vertical xrod for a`length equal through thev'medium bf two screw sleeves and a toothedvpinion and a rack.

- This device has several drawbacks including the necessity for anauxiliary device for effecting the product Y D v f Y Moreover, the sightD mustrbe provided twice, once for producing the elevation for the firstdrum and oncev for forming the product The apparatuswhich constitutesthe subject matter of the present inventionhas for its-object'todispense with the auxlll'ary device and to necessltateonly one operationfor introducing the value D in the apparatus.. It comprises chieiy an.internally and externally threaded ring which supportsthe cylindricalboxand is adapted to be raised and lowered in the casing without beingable .to rotate; a cylindrical rack engages extern'ally with thethreaded ring-and internalwith the pinion which controls the radialdisplacement of thecarriage. The said rack rotates integrally with speedabacus but is not able to effect vertical displacements relatively tothe said sleeve. The speed abacus is controlled by any suitable meanssuch as endless screw and helicoidal teeth. An internally threaded crownmeshing with the threaded ring which supports the cylindrical box allowsofgiving the elevation. It controls at thesame time theVerticaldisplaceway of example inFigures 3 to y10.

ment in cooperation with the` rear sight of a front index whichdisplaces the speed curves. When the rear sight is set,'the vspeedthrough the vaxis'of the sight-controlshaft about on the line 3-3 ofEig. 5. f

Fig. 4 is a cross-sectionalverticalview through the axis of the vseed-control shaft, about on the line 4-4 o Fig. '5. f

Figure 5 is a transverse cross-section of the apparatus about on line5-5 of Fig'. 3.

Figure 6 is a perspective View thereof.

Figures 7 t-o 9 show the simplified form of execution for firing onshort and on ylong ranges.

Figure 7 is a cross-sectional vertical'view vpassing through the axis ofthe cylindrical.

box.

Figure 8 is a simplified transversal crossl section showing the controlof'the carriage. Figure 9 is a view from above.

Figure 10 shows a form of speed abacus developed in a horizontal plane.

Referring first to Figures 3 to 6, We have shown merely the part of thecorrector which serves to set in vplace the universal joint connectedwith the arm fo carrying the sight device of the corrector andcorresponding to the oint f of Figure 2.

T is part of the corrector comprises a Acasing 1 inside which may rise,fall and 17otate the cylindrical box 2. In this cylindrical box, thecarriage 3 may move radially; this carriage shows a toothwork meshingwith the'pinion 4 (Figure 3). Another carriage 5, sliding with referenceto the carriage 3, is provided with a vertical sleeve 6 containingtherod 7 carrying the universal joint corresponding to pointf. Thedirection-arrow is shown at 10. The rotary motion of the cylindrical boxin its casing is obtained by acting `on this arrow 10; when the tip lofthe arrow is raised or lowered according to the raising o r fallingmotion of the aircraft,

it causes the carriages to move one with reference to the other throughthe agency of a,

mechanism which is disclosed in Patent 1,651,093 before mentioned.

The pinion 4 meshes with -a circular rack l 8 whereby only the verticalmovements yof the rack produce a rotation of the pinion 4, the

rotary movements having no action'. Outwardly the circular rack isprovided with a thread meshing with the inner'thread of a ring 9provided with an inner and an outer thread. .This ring, which. forms thechief part of the present arrangement, carries the Acylindrical box 2 ina manner such as will allowits rotation. But the ring itself is onlyadapted to rise and fall in the casing, without rotating with referenceto this casmg. The outer thread of the ring 9 meshes with the innerthread of a sun-wheel 11 mounted in a manner y'such as to be adapted to4rotate in the casing 1 but without rising or falling.

The rotation of the sun-wheel 11 is controlled bythe pinion ,12(Figure`f-4) keyed to the` stub-shaftl 13 the rotation lof which isobtained through the range knob 14 (Figures 5 and 6). The verticaldisplacements of the rin are given out outwardly by the pointer 16Figure 6). l

The circular rack 8 is connected in rotation with'the abacus-cylinder 15 by means 'of A "f 1,915,191l

visible through the apertures -18 provided inthe casing. To this nd(Figure 3) it meshes with a pinion 19 keyed to the stub sha-ft 21whichis caused to rotate throughsuitable intermediarygear wheels by thespeed-control '10 knob 22 (Figures 5 and 6).

I lhas been indicated in kilometers on each With regard to the speedabacus, the speed vcurve to which speed this curve corresponds. Each` ofthese curves is traced through a point. Lengths proportional to thevalues' of Lengths proportional to the'value ctv-abiti).- for D-=2400and Y=30 Isiggghts corresponding to dierent ranges D are provided asordinates, a range-graduation being provided at the ordinate axis.

' (t+e)V 7- al'e plO- 'vided as absciss (ebeing 'a supplementarycorrection for taking i'nto consideration the lo'st time inmanoeuvering). In order to fix and V= 30 kilometers per hour, theoperation AprovidingI the sight will bring the index 16 in coincidencewith the line'2400. The rotation ofthe abacus will bring the point M inM1 to the end of the index 16. The angle of rotation will beproportional to MM1, hence kilometers. f Y, l

The working of the apparatus isas follows: `W'e begin by setting downthe range through rotationv 'of the sight knob 14. The shaft 13` (Figure4) and the sun-wheel 11 are thus rotated. The rotation of this sunwheelhas for its object," as the ring 9 cannot rotate in the casing, to makethis ring rise -or fall.r It

raises or lowers the whole of the box 2 with rall its contents and inparticular the ra'ck 8 scale provided on the ledgeof-the aperture 18 andthis displacement is stopped/when the de.-:

' sired range is ,reachedor the scale.

``rotation of this knob causes the'rotation ofthe shaft 21 (Figure v3)and through'the agency of the pinion 19 the rotation of the abacusf Weact then on'the speed knob 22. The

cylinder 15. But this rotation of the abacusv cylinder 15,causes therack 8 to rotate. vThe latter, as the ring 9 cannot rotate, rises orfalls 'as it rotates with reference to this ring. c This rise andfallrauses arotation of the'pinion 4 and a radial displacement of thecarriage 3 and of the rod 7.v The action on the knob 22 is continueduntil the desired speed abacus 17 comes into coincidence with thepointer 16. Obviously the rotation reguired for'this coincidencedependson the position of the index 16 with reference to its scale andconsequently on the range.

It is thus apparent that the range has'an aetion on the radialdisplacement of the carr1 ures 7 t 9 is intended for firing with acertain "number of typical speeds and over two kinds of ranges only,short ranges and long ranges.

Inthls apparatus, a casing 31 is also proage. y

The simpliied form of execution of Fig- `vided wherein may movevertically the cylindrical box 32 inside which moves radially.thecarriage 33 provided with a toothwork meshing withthe pinion 34. 1Another carriage 35 slides with reference to the carriagev 33;I it isprovided with a vertical sleeve 36 containing the rod 37. Thedirectingjarrow the ideas, let us suppose that D=240O meters callyinside thecasing 31; this sun-wheel is outwardly provided with notches42 adapted to be engaged by a tooth 43 (Figures 7 and 9) forming-part ofa handle 44 urged forward by' a spring 45 so-asto make the tooth 43engage a notch 42. l3nt this engagement can be provided only if thetooth 43 is in front of one of the notches 42 corresponding to a givenspeed ,except in such cases, thetooth 43 ,l

moves round the sun-wheel 41. The springurged handle 44 is mounted onanaxis 46.

integral with an inwardly threaded sun-wheel 47, the thread of whichmeshes with the outerv thread 48 of the circular rack, the partforiningthe rack being to the inside and meshing with the pinion 34 fordisplacing the carriage. Thi), rack 48 is adapted to move only verticaly.-

The apparatus is4 made use of in the lfollowing manner :l supposing` thehandle 44 is in the notch 42 tothe extreme right, it is ,pulled so as todisengage the tooth 43. The handle is then turned towards the left so asto bring it in front of the notch 42 corresponding-tothe speed of thetarget (proper or eii'ective speed. according to/ the firing methodused); By'actingthus, the sun-wheel 47 is and the' tooth 43 engages thedesired'notch 42. The` handle is now rotated to the end of its pathtowards the right or the lettta'ccord-l ing as to whether it is desiredto fire over short bis ` fall without rotating inside the casing, a

' the box adapted to -.be .displace meshin wheel.

or long ranges. Under these circumstances,v the handle 44 drivessimultaneously the sun- .wheel 47 and the sun-wheel 41. yWe providethus, through the sun-.wheel 47, a complemental-y lrise or lowering ofthe rack 48 which introduces the distance in the eccentri'city, andthrough the sun-wheel 41 a rise orlowei-, ing of the ring 38 andconsequently of the cylindrical box 32, which provides the sight.

What we Ic`lairrrisz 1. A corrector for the 'craft guns comprisingv alconstantly vertical casing secured to the gun, an inwardly and outwardlythreaded ring` adaptedto rise and fall without rotating inside thecasing, a cylindrical box carried by ther'ing inside saidcasing, meansfor displacingsaid -box vertically in the casing inaccordance with therange of the target, a carriage carried by cording to the speed andrange of the target along 'a radiusof the box parallel to theproject-ion'of the pathof the-aircraft, a rod carried. by the carriageand pivotally connected with a stationary point ofthe gun, sighting.means carried by said rod, a pinion controlling the radial displacementofA the carriage, arack meshing with thepinion and provided with anouter'thread engaging theinner thread of the ring, a cylinder providedWith speed curves adapted -to rotate with the rack without movingvertically withv it, .a speed control lpnobcontrolling the rotation ofthe cylinder, an inwardly threaded sun-wheel mounted inside', the casingand with the outer thread of the ring tiring of anti-air-v u therein ac.

and a sight control knob controlling the sun` 2. A corrector forthetiring of anti-aircraft guns comprising a constantly 'vertical casingsecured to the gun, an inwardly and'` outwardly threaded ring adapted torise and' cylindrieal'box carried by thering inside. said casing, meansfor displacin said boxl vertically in the casing in accor ance with the`range of the target, a carriage. .carried by the box adaptedto bedisplaced therein' according to the speedand range of the target along'aradius of the bo'x parallel to the projection of the path of theaircrafta, rod carriedby'the carriage and lpivotally connected withastationary point 'of the gun,

' sighting means carried by said rod, a;pin'

ion controlling the radial displacement of the carriage, a rack meshingwith the pin ion and-provided withan outer thread engaging the 'innerthread'of the ring, a cyl- -inder provided with speed curves adapted torotate with the'V rack wit-hout moving vertically with it,l thecasingbeing provided with -Van aperture allowing the speed curves to beY Y seen. and carrying along one edge a scale of ranges, a pointercarried by the 100x-cooperating with the scale on' the casing, a speed

